Sun-kissed harmonies, funk-flecked guitar lines and — whisper it — a saxophone workout all make an appearance on “Hesitation Marks,” a surprising new offering from Trent Reznor’s Nine Inch Nails after a lengthy, self-imposed hiatus.

In the five years since the industrial rockers’ last album, the 48-year old Reznor has won an Academy Award for his soundtrack work on “The Social Network,” married musician Mariqueen Maandig and become a father to two young boys. These developments are apparent in the makeup of “Hesitation Marks,” where chinks of light occasionally penetrate the darkness so prevalent on the band’s previous releases.

“Wish me well – I’ve become something else (just as well, really)” sings the front man on the surprisingly poppy track “Everything,” which has spawned a fan-made video of Reznor riding a white unicorn in front of a rainbow. Elsewhere, the falsetto-vocals and staccato guitar line of “All Time Low,” and the brass stabs that punctuate the shuffling rhythm of “While I’m Still Here” suggest Reznor is leading his troops to markedly new terrain.

The band’s trademark brand of decaying electronica and discordant noise has not been ditched altogether, though. The opening four tracks play like a “best of” Nine Inch Nails. Lead-off single “Came Back Haunted” couples existential lyrics with aggressive synths and a searing guitar line. And spiritual ballad “Find My Way” echoes the group’s 1995 single “Hurt.”

The intriguing “Hesitation Marks” often resembles a ship trying to break free from its moorings. Once the final rope snaps, Reznor promises to deliver one hell of a trip – but, until then, longtime fans of Nine Inch Nails will be relieved to find that underneath the album’s occasionally bright, brash surface there’s still a heart of darkness beating strong and steady.